Background of the Invention
[0001] The present invention relates to a method and apparatus for transmitting mechanical
movement from one location to another utilizing hydraulic fluid as the transmitting
means. More particularly, the invention relates to a force transmission device employing
interconnected hydraulic cylinders wherein pressure generated in one cylinder is transmitted
to the other cylinder to achieve a desired movement or operation at a location remote
from that at which the pressure force originates.
[0002] Such a device may be used for effecting mechanical operations in a motor vehicle
such, for example, as actuating a mechanical clutch of the vehicle. In such use, a
"master" cylinder is utilized to originate pressure flow which is transmitted by a
conduit to a "slave" cylinder having an output member connected to the clutch release
mechanism.
[0003] Master cylinder assemblies typically include either an integral reservoir structure
in which the reservoir is positioned immediately adjacent the main body or shell of
the master cylinder assembly or a remote reservoir structure in which a spout is provided
immediately adjacent the shell of the master cylinder and the spout connects with
a flexible conduit which in turn connects with a remotely relocated reservoir. In
the past, the shell of the master cylinder has been uniquely constructed so as to
be dedicated to association with either an integral reservoir or a remote reservoir.
In effect, two distinct master cylinders and two distinct reservoirs have been required
to accommodate the requirements of vehicle manufacturing customers.
[0004] DE-A-2205402 discloses a master cylinder which can be equipped with either an integral
or remote reservoir through a reservoir outlet in a side wall of the master cylinder.
Although more adaptable than previous master cylinders such a construction which uses
a side wall connection with its reservoir is still not ideal.
[0005] EP-A-0 285 255 discloses a master cylinder comprising a reservoir outlet in an end
wall of the shell.
Summary of the invention
[0006] This invention is directed to a method of providing a master cylinder assembly which
allows an identical master cylinder shell to be utilized with either an integral reservoir
or a remote reservoir in a particularly adaptable manner.
[0007] Thus according to the present invention there is provided a method of providing master
cylinder assemblies of both integral and remote reservoir design comprising:-
providing a master cylinder having an elongated tubular shell defining a bore with
a piston slidably received in the bore, an opening at one end of the shell for passage
of a piston rod for driving engagement with the piston, the other end of the bore
being closed to define a working chamber in combination with the piston , a high pressure
working outlet opening into the working chamber proximate said other end of the shell
for connection to a conduit connecting to a slave cylinder, and a reservoir outlet
comprising a socket formed in an end wall of the shell proximate said other end and
opening into the working chamber;
providing valve means at a location proximate to the reservoir outlet for closing
off said reservoir outlet on initial movement of the piston towards said other end
of the shell to pressurise the working chamber;
providing a remote reservoir connected to a spout by a conduit, the spout having a
spout fitting sized to fit in the reservoir outlet socket to connect the shell to
the spout and provide fluid communication between the working chamber and the remote
reservoir;
providing an integral reservoir having a reservoir fitting integrally formed therewith
and corresponding to the spout fitting and sized to fit in the reservoir outlet socket
to connect the shell to the integral reservoir and provide fluid communication between
the working chamber and the integral, reservoir;
connecting the spout to the shell utilizing the spout fitting and the reservoir outlet
to constitute a master cylinder assembly including a spout for connection by a conduit
to the remote reservoir; and
alternatively connecting the integral reservoir to the shell utilizing the reservoir
fitting and the reservoir outlet to constitute a master cylinder assembly including
an integral reservoir.
[0008] Thus the method of the present invention can provide a master cylinder assembly with
either an integral or remote reservoir and whose working chamber outlet configuration
is proximate to the other end of the shell.
[0009] The integrally formed reservoir fitting and the spout may have an L configuration
with one leg of the configuration in each case defining a plug for receipt in the
reservoir outlet socket and the other leg of the configuration providing communication
with the reservoir.
[0010] The valve means may include a valve member operatively connected with the piston
and which is moved to cover the reservoir outlet during the initial movement of the
piston towards said other end of the shell to pressurise the working chamber.
[0011] In such an arrangement after closing-off of the reservoir outlet by the valve member
further movement of the piston towards said other end of the shell results in displacement
of the piston relative to the valve member.
Brief Description of the Drawing
[0012]
FIGURE 1 is an exploded view of a master cylinder assembly according to the invention;
FIGURES 2 and 3 are longitudinal cross-sectional views showing the manner in which
the master cylinder is configured to provide a remote reservoir construction; and
FIGURES 4 and 5 are longitudinal cross-sectional views showing the manner in which
the invention master cylinder is configured to provide an integral reservoir construction.
Detailed Description of the Preferred Embodiment
[0013] The invention master cylinder apparatus is disclosed as forming a part of a hydraulic
clutch control apparatus for controlling the clutch of a motor vehicle. The clutch
control apparatus includes a master cylinder apparatus 10 for operative association
with the clutch pedal 12 of the motor vehicle and a slave cylinder assembly 14 for
operative association with the clutch release lever 16 of the motor vehicle so that,
in known manner, depression and release of clutch pedal 12 operates via the clutch
control apparatus to extend and retract the piston rod 18 of the slave cylinder assembly
and thereby disengage and engage the clutch.
[0014] Master cylinder apparatus 10, broadly considered, includes a master cylinder assembly
20, an integral reservoir structure 22, and a remots reservoir assembly 24.
[0015] Master cylinder assembly 20 includes a tubular shell or body 26, a piston 28, a pistcn
rod 30, and a valve assembly 32.
[0016] Shell 26 is formed of a suitable plastic material, is elongated, and includes a main
body 26a defining a central axial bore 26b including an open end 26c. A flange structure
26d on the exterior of the shell is utilized in known manner to rigidly mount the
shell 26 in the firewall 33 of the motor vehicle Shell 26 further defines a high pressure
outlet 26e proximate the closed rearward end 26f of the shell for connection in known
manner to a hose or conduit 34 connected to the inlet 14a of the slave cylinder 14.
A fitting or socket 26g is provided in the closed end 26f of the shell and includes
a bore 26h concentric with the central axis 36 of the shell and opening in bore 26b;
a counterbore 26i; and a further counterbore 26j opening in the rear face 26k of the
shell.
[0017] Piston 28 is slidably mounted in core 25b and includes a recess 28a proximate its
forward end 28b for receipt of the rearward end 30a of piston rod 30. The other or
forward end 30b of the piston rod is pivotally secured in known manner to the clutch
pedal 12 so that depression of the clutch pedal operates to move the piston 28 rearwardly
within bore 26b so as to deliver pressurized hydraulic fluid via fitting 26e and hose
34 slave cylinder 14 for extension of slave cylinder piston rod 18 and operation of
clutch release lever 16 in a manner to disengage the clutch. The rearward movement
of the piston 28 in bore 26b is resisted in known manner by a coil spring 38.
[0018] Valve assembly 32 is positioned in bore 26b proximate bore 26h and includes an open
structure cage 40, a coil spring 41, and a valve stem structure 42. Cage 40 includes
a flange portion 40a against which spring 38 bears so as to retain the cage in position
adjacent the rear end of bore 26b. Valve stem structure 42 includes a main body stem
portion 42a, a head portion 42b, and a valve portion 42c positioned within cage 40
in proximity to bore 26h and engaged by spring 41. Head 42b coacts with a rearward
piston structure 28c so that the piston is free to move rearwardly within the bore
26b relative to stem 42a whereas forward movement of the piston within the bore 26b
engages head 42b and pulls the valve 42c away from bore 26h against the resistance
of spring 41. In this manner, the valve 42c acts, under the urging of spring 41, to
seal the bore 26h in response to rearward movement of the piston upon depression of
the clutch pedal so as not to interfere with the discharge of pressurized fluid from
the fitting 26e whereas forward return movement of the piston upon release of the
clutch pedal acts to pull the valve 42c clear of bore 26h against the resistance of
spring 41 and allow fluid from the reservoir to flow through cage 40 and fill bore
26b behind the advancing piston.
[0019] Reservoir structure 22 is formed of a suitable plastic material, such as the plastic
material of the shell 26, and includes a main body bowl portion 22a, a spout portion
22b, and a cover or lid 44 adapted to be removably secured to the upper end of the
bowl portion 22a utilizing threads 22c coacting with threads on the lid.
[0020] Spout portion 22b has an L-shaped configuration and includes a vertical leg 22d and
a horizontal leg 22e. Vertical leg 22d includes a central bore 22f communicating at
its upper end with the central cavity 22g of the bowl portion 22a and horizontal leg
22e includes a central horizontal bore 22h communicating at one end with the lower
end of bore 22f and opening at its other end in the front face 22i of the horizontal
leg. The front end of the horizontal leg 22e comprises a coacting fitting with respect
to shell fitting 26g and, specifically, has a plug configuration of circular cross
section including a relatively large diameter plug section 22j and a concentric relatively
small diameter plug section 22k. Large diameter plug section 22j includes an external
groove 22l for coaction with an O-ring 45. Relatively small diameter section 22k has
a size and configuration generally corresponding to the size and configuration of
the counterbore 26i of shell socket 26g and relatively large diameter section 22j
has a size and configuration generally corresponding to the size and configuration
of the counterbore 26j of shell socket 26g so that the plug fitting defined by the
leading end of the horizontal leg of the spout of the reservoir may be plugged into
the socket fitting 26g to seat section 22i in counterbore 26i and seat section 22j
in counterbore 26j so as to provide fluid communication between the shell bore 26b
and the reservoir cavity 22g via bores 22f, 22h, and 26h.
[0021] Remote reservoir assembly 24 includes a spout 46, a hose 48, and a remote reservoir
50.
[0022] Spout 46 is formed of a suitable plastic material, such as the plastic material of
shell 26 and reservoir structure 22, and has an L-configuration including a vertical
leg 46a and a horizontal leg 46b. Vertical leg 46a includes a central bore 46c opening
at the upper end of the vertical leg, and barbs or serrations 46d are provided on
the exterior surface of the vertical leg.
[0023] Horizontal leg 46b includes a central bore 46e communicating at one end with bore
46c and opening at its other end in the front face 46f of the horizontal leg.
[0024] The front end of lower leg 46b comprises a coacting fitting with respect to socket
fitting 26g and, specifically, has a plug configuration corresponding precisely to
the plug configuration of the front end of the horizontal leg 22e of the spout portion
of reservoir structure 22 and includes a relatively large diameter section 46g and
a relatively small diameter section 46h. Section 46g has a size and configuration
corresponding to the size and configuration of the counterbore 26a of shell socket
26g and section 46h has a size and configuration corresponding to the size and configuration
of counterbore 26i of shell socket 26g so that the plug fitting defined by the leading
end of the horizontal leg of spout 46 may be plugged into socket fitting 26g to seat
section 46h in counterbore 26i and seat section 46g in counterbore 26j and provide
fluid communication between the shell bore 26b and spout bore 46c via bores 46e and
26h. An O-ring 45 seats in an external groove 46i of the plug to facilitate the seal
between the plug and the cylinder.
[0025] Hose 48 is formed of any suitable resilient and flexible material and is adapted
to be removably positioned at its lower end 48a over the upper end of vertical leg
46a of spout 46 utilizing barbs 46d.
[0026] Remote reservoir 50 is formed of a suitable plastic material, such as the plastic
of shell 26 and reservoir structure 22, and includes a main body bore portion 50a,
a lower spout portion 50b providing a central bore 50c communicating with the interior
cavity 50d of bore 50a, and a removable cap or lid 52. The upper end 48b of hose 48
is removably secured to fitting 50b utilizing barbs 50e defined on the exterior surface
of the fitting.
[0027] It will be seen that the invention provides an apparatus and methodology for providing
both a master cylinder remote reservoir assembly and a master cylinder integral reservoir
assembly utilizing precisely the same main body shell unit. Specifically, if it is
desired to provide a remote reservoir assembly, a spout 46 is positioned in the socket
26g of the shell and suitably secured in position and if it is desired to provide
an integral reservoir assembly the spout portion 22b of an integral reservoir 22 is
positioned in socket 26g and suitably secured therein. Securement of the plug end
of the spout 46 or the plug end of the spout portion of the reservoir structure 22
may be achieved through the use of a snap fit, the use of a mounting clip, or, as
shown, by welding. The welding may in turn be accomplished in a variety of manners
such, for example, as sonic welding.
[0028] Although a preferred embodiment of the invention has been illustrated and described
in detail, it will be apparent that various changes may be made and disclosed in the
embodiment without departing from the scope of the invention as claimed.
1. A method of providing master cylinder assemblies of both integral and remote reservoir
design comprising:-
providing a master cylinder (20) having an elongated tubular shell (26) defining a
bore (26b) with a piston (28) slidably received in the bore, an opening at one end
(26c) of the shell for passage of a piston rod (30) for driving engagement with the
piston, the other end (26f) of the bore (26b) being closed to define a working chamber
in combination with the piston , a high pressure working outlet (26e) opening into
the working chamber proximate said other end (26f) of the shell for connection to
a conduit (34) connecting to a slave cylinder (14), and a reservoir outlet (26g)comprising
a socket formed in an end wall of the shell proximate said other end (26f) and opening
into the working chamber;
providing valve means (32) at a location proximate to the reservoir outlet (26g) for
closing off said reservoir outlet on initial movement of the piston (28) towards said
other end (26f) of the shell to pressurise the working chamber;
providing a remote reservoir (50) connected to a spout (46) by a conduit (48), the
spout having a spout fitting (46b) sized to fit in the reservoir outlet socket. (26g)
to connect the shell (26) to the spout (46) and provide fluid communication between
the working chamber and the remote reservoir;
providing an integral reservoir (22) having a reservoir fitting(22b)integrally formed
therewith and corresponding to the spout fitting (46b) and sized to fit in the reservoir
outlet socket (26g) to connect the shell (26) to the integral reservoir (22), and
provide fluid communication between the working chamber and the integral reservoir;
connecting the spout (46) to the shell (26) utilizing the spout fitting (46b) and
the reservoir outlet (26g) to constitute a master cylinder assembly including a spout
(46) for connection by a conduit (48) to the remote reservoir (50); and
alternatively connecting the integral reservoir (22) to the shell (26) utilizing the
reservoir fitting (22b) and the reservoir outlet (26g) to constitute a master cylinder
assembly including an integral reservoir (22).
2. A method according to claim 1 characterised in that the integrally formed reservoir fitting (22b) and the spout (46) have an L configuration
with one leg (46b,22e) of the configuration in each case defining a plug for receipt
in the reservoir outlet socket (26g) and the other leg (46a,22d) of the configuration
providing communication with the reservoir (50,22).
3. A method according to claim 1 or 2 characterised in that the valve means (32) includes a valve member (42) operatively connected with the
piston (28) and which is moved to cover the reservoir outlet (26g,26h) during the
initial movement of the piston towards said other end of the shell to pressurise the
working chamber.
4. A method according to claim 3 characterised in that after closing off of the reservoir outlet (26g,26h) by the valve member (42) further
movement of the piston (28) towards said other end (26f) of the shell (26) results
in displacement of the piston (28) relative to the valve member (42).
1. Verfahren zum Zur-Verfügung-Stellen von Hauptzylinderanordnungen sowohl in der Ausführung
mit integralem Vorratsbehälter als auch mit fernem Vorratsbehälter mit folgenden Schritten:
Zur-Verfügung-Stellen eines Hauptzylinders (20) mit einer länglichen Rohrhülle (26),
die eine Bohrung (26b) bestimmt, wobei in der Bohrung ein Kolben (28) verschiebbar
aufgenommen ist, einer Öffnung an einem Ende (26c) der Hülle zum Durchtritt einer
Kolbenstange (30) zum treibenden Eingriff mit dem Kolben, wobei das andere Ende (26f)
der Bohrung (26b) verschlossen ist, um in Kombination mit dem Kolben einen Arbeitsraum
zu bestimmen, einem Hochdruckarbeitsauslaß (26e), der sich in den Arbeitsraum in der
Nähe des anderen Endes (26f) der Hülle zum Anschluß an eine Leitung (34) öffnet, die
an einem Nehmerzylinder (14) angeschlossen ist, und einem Vorratsbehälterauslaß (26g),
der eine Muffe aufweist, die in einer Endwand der Hülle in der Nähe des anderen Endes
(26f) ausgebildet ist, und der sich in den Arbeitsraum öffnet;
Zur-Verfügung-Stellen einer Ventilvorrichtung (32) an einem Ort in der Nähe von dem
Vorratsbehälterauslaß (26g) zum Verschließen des Vorratsbehälterauslasses bei einer
Anfangsbewegung des Kolbens (28) in Richtung des anderen Endes (26f) der Hülle, um
den Arbeitsraum unter Druck zu setzen;
Zur-Verfügung-Stellen eines fernen Vorratsbehälters (50), der an einem Auslauf (46)
über eine Leitung (48) angeschlossen ist, wobei der Auslauf einen Auslaufbeschlag
(46b) aufweist, der bemessen ist, um in die Vorratsbehälterauslaßmuffe (26g) zu passen,
um die Hülle (26) an den Auslauf (46) anzuschließen und eine Fluidverbindung zwischen
der Arbeitskammer und dem fernen Vorratsbehälter zu schaffen;
Zur-Verfügung-Stellen eines integralen Vorratsbehälters (22) mit einem Vorratsbehälterbeschlag
(22b), der einstückig damit ausgebildet ist und dem Auslaufbeschlag (46b) entspricht
und bemessen ist, um in die Vorratsbehälterauslaßmuffe (26g) zu passen, um die Hülle
(26) an den integralen Vorratsbehälter (22) anzuschließen und eine Fluidverbindung
zwischen der Arbeitskammer und dem integralen Vorratsbehälter zu schaffen;
Anschließen des Auslaufs (46) an die Hülle (26) unter Verwendung des Auslaufbeschlags
(46b) und an den Vorratsbehälterauslaß (26g), um eine Hauptzylinderanordnung mit einem
Auslauf (46) zum Anschluß an eine Leitung (48) zu dem fernen Vorratsbehälter (50)
auszubilden; und
alternativ Anschließen des integralen Vorratsbehälters (22) an die Hülle (26) unter
Verwendung des Vorratsbehälterbeschlags (22b) und an den Vorratsbehälterauslaß (26g),
um eine Hauptzylinderanordnung mit einem integralen Vorratsbehälter (22) auszubilden.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß der integral ausgebildete Vorratsbehälterbeschlag (22b) und der Auslauf (46) eine
L-Konfiguration haben, wobei in jedem Fall ein Bein (46b, 22e) der Konfiguration einen
Stopfen für die Aufnahme in der Vorratsbehälterauslaßmuffe (26g) bestimmt, und das
andere Bein (46a, 22d) der Konfiguration eine Verbindung mit dem Vorratsbehälter (50,
22) schafft.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Ventilvorrichtung (32) ein Ventilglied (42) umfaßt, das betriebsfähig mit dem
Kolben (28) verbunden ist, und das bewegt wird, um den Vorratsbehälterauslaß (26g,
26h) während der Anfangsbewegung des Kolbens in Richtung des anderen Endes der Hülle
zu überfahren, um die Arbeitskammer unter Druck zu setzen.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß nach dem Verschließen des Vorratsbehälterauslasses (26g, 26h) durch das Ventilglied
(42) eine weitere Bewegung des Kolbens (28) in Richtung des anderen Endes (26f) der
Hülle (26) zu einer Verschiebung des Kolbens (28) relativ zu dem Ventilglied (42)
führt.
1. Procédé pour réaliser des ensembles de maître-cylindre avec une conception de réservoir
à la fois d'un seul tenant et à distance comprenant :
la prévision d'un maître-cylindre (20) comportant une chemise tubulaire allongée (26)
définissant un alésage (26b) avec un piston (28) reçu de manière coulissante dans
l'alésage, une ouverture à une extrémité (26c) de la chemise pour le passage d'une
tige de piston (30) pour la mise en prise d'entraînement avec le piston, l'autre extrémité
(26f) de l'alésage (26b) étant fermée afin de définir une chambre de travail en combinaison
avec le piston, une ouverture de sortie de chambre de travail haute pression (26e)
dans la chambre de travail à proximité de ladite autre extrémité (26f) de la chemise
pour le raccordement à un conduit (34) raccordant à un cylindre récepteur (14), et
une sortie de réservoir (26g) comprenant une cavité formée dans une paroi d'extrémité
de la chemise à proximité de ladite autre extrémité (26f) et s'ouvrant dans la chambre
de travail ;
la prévision de moyens formant valve (32) à un emplacement à proximité de la sortie
de réservoir (26g) pour fermer ladite sortie de réservoir lors du mouvement initial
du piston (28) vers ladite autre extrémité (26f) de la chemise afin de mettre la chambre
de travail sous pression ;
la prévision d'un réservoir à distance (50) raccordé à un bec (46) par un conduit
(48), le bec comportant un raccord de bec (46b) dimensionné pour s'insérer dans la
cavité de sortie de réservoir (26g) pour raccorder la chemise (26) au bec (46) et
pour permettre une communication de fluide entre la chambre de travail et le réservoir
à distance ;
la prévision d'un réservoir d'un seul tenant (22) comportant un raccord de réservoir
(22b) formé d'un seul tenant avec celui-ci et correspondant au raccord de bec (46b)
et dimensionné pour s'insérer dans la cavité de sortie de réservoir (26g) pour raccorder
la chemise (26) au réservoir d'un seul tenant (22) et pour permettre une communication
de fluide entre la chambre de travail et le réservoir d'un seul tenant ;
le raccordement du bec (46) à la chemise (26) en utilisant le raccord de bec (46b)
et la sortie de réservoir (26g) pour constituer un ensemble de maître-cylindre comprenant
un bec (46) pour le raccordement par un conduit (48) au réservoir à distance (50)
; et
en variante, le raccordement du réservoir d'un seul tenant (22) à la chemise (26)
en utilisant le raccord de réservoir (22b) et la sortie de réservoir (26g) pour constituer
un ensemble de maître-cylindre comprenant un réservoir d'un seul tenant (22).
2. Procédé selon la revendication 1, caractérisé en ce que le raccord de réservoir formé d'un seul tenant (22b) et le bec (46) présentent une
configuration en L avec un bras (46b, 22e) de la configuration définissant dans chaque
cas un bouchon destiné à être reçu dans la cavité de sortie de réservoir (26g) et
l'autre bras (46a, 22d) de la configuration permettant la communication avec le réservoir
(50, 22).
3. Procédé selon la revendication 1 ou 2, caractérisé en ce que les moyens formant valve (32) comprennent un élément de valve (42) raccordé de manière
fonctionnelle au piston (28) et qui est déplacé de manière à recouvrir la sortie de
réservoir (26g, 26h) pendant le mouvement initial du piston vers ladite autre extrémité
de la chemise afin de mettre la chambre de travail sous pression.
4. Procédé selon la revendication 3, caractérisé en ce que, après la fermeture de la sortie de réservoir (26g, 26h) par l'élément de valve (42),
un mouvement supplémentaire du piston (28) vers ladite autre extrémité (26f) de la
chemise (26) résulte en le déplacement du piston (28) par rapport à l'élément formant
valve (42).